(i) Technical Field
The present invention relates to a polyimide precursor composition and a method for producing a polyimide precursor composition.
(ii) Related Art
Polyimide resins, which have high durability and high heat resistance, are widely used in various applications, for example, electronic materials for insulating layers and flexible substrates for forming electronic circuits, components, and transfer belts and fixing belts of electrophotographic apparatuses.
Such polyimide resins, which are difficult to soften by heating, are not easy to shape through melting. In addition, polyimide resins, which are difficult to dissolve in solvents, are not easy to shape by preparing, applying, and drying solutions of polyimide resins. For these reasons, shaping of polyimide resins is performed by preparing polyimide precursor compositions containing polyimide precursors (polyamic acids) dissolved in solvents, and subjecting the polyimide precursor compositions to drying and imidization by heat treatment. However, there are only a limited number of solvents that dissolve polyimide precursors.
As solvents that dissolve polyimide precursors and have lower boiling points than ordinary aprotic polar solvents, solvent mixtures are used that each contain at least one of a water-soluble ether and a water-soluble ketone as a main solvent and further contain a water-soluble alcohol or water.